1. Technical Field
The present invention relates to magnetic write heads for writing to a magnetic storage medium. More particularly, this invention relates to reducing the effects of stray flux from an external source such as is produced by a neighboring write head.
2. Description of the Prior Art
Magnetic storage and magnetic recording are terms referring to the storage of data on a magnetic medium. In magnetic recording, magnetic patterns are recorded onto a magnetizable material to store the data. The information is accessed using one or more read/write heads. Magnetic storage devices, primarily hard disks and magnetic tape drives, are widely used to store digital information such as software, audio, and video data.
Heads for use with magnetic storage media typically include a writer and a reader that respectively record and detect magnetic domains in a medium in proximity to the head. A writer typically has a coil with one or more turns wrapped around a ferromagnetic yoke. To operate a writer, an electric current is passed through the coil, producing a magnetic field in the yoke. This magnetic field bridges a non-magnetic gap at the end of the yoke and also extends partly into the storage medium. For a perpendicular writer, a soft magnetic underlayer can be employed in the storage medium such that the write field extends between the yoke and the soft underlayer. When the write field exceeds the coercivity of the medium, the medium becomes magnetized. As the write current is reversed while the head moves over the medium, a magnetic transition is created. These transitions form the bits of digital data that are detected with the read head.
In some magnetic recording systems, such as magnetic tape drives, multiple writers are used simultaneously to enable writing data at a high data rate. The spacing between these write heads is determined by a recording format of the tape. In current products this spacing is 166.5 micro meters. Future recording formats may require heads on a tighter pitch to enable both higher areal density and higher data rate. However, there are limitations on how small the element pitch can be.
When two or more writers are in proximity, the magnetic flux generated by any writer may enter the yoke of another writer. This may degrade the quality of the patterns recorded by the magnetic writers. This coupling between writers is referred to as “crosstalk” and poses a limitation on writer pitch. Therefore, there is a need for a solution which reduces the effects of stray flux on write quality.